Vladimir K. Zworykin

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Vladimir K. Zworykin : biography

July 29, 1888 – July 29, 1982

Vladimir Zworykin demonstrates electronic television (1929).

Vladimir Zworykin described cathode ray tubes as both transmitter and receiver. The operation, whose basic thrust was to prevent the emission of electrons between scansion cycles, was reminiscent of A. A. Campbell Swinton’s proposal published in Nature in June 1908.A. A. CAMPBELL SWINTON (1908) A. A. CAMPBELL SWINTON (1908) This would result in the television signal being derived from the modest number of electrons released at the instant the cathode ray swept over an image point.

The demonstration given by V. Zworykin sometime in late 1925 or early 1926 — not in 1923, as popular accounts would have it — was far from a success with the Westinghouse management, even though it showed the possibilities inherent in a system based on the Braun tube. Although he was told by management to "devote his time to more practical endeavours", Zworykin continued his efforts to perfect his system. As attested to by his own writing, including his doctoral dissertation of 1926, earning him a PhD from the University of Pittsburgh, his experiments were directed at improving the output of photoelectric cells.

There were, however, limits to how far one could go along these lines, and so, in 1929, V. Zworykin returned to vibrating mirrors and facsimile transmission, filing patents describing these. At this time, however, he was also experimenting with an improved cathode ray receiving tube, filing a patent application for this in November 1929, and introducing the new receiver that he named "Kinescope", reading a paper two days later at a convention of the Institute of Radio Engineers.

Having developed the prototype of the receiver by December, Zworykin met David Sarnoff, who eventually hired him and put him in charge of television development for RCA at their newly established laboratories in Camden, New Jersey.

The move to the laboratories occurred in the spring of 1930 and the difficult task of developing a transmitter could begin. There was an in-house evaluation in mid-1930, where the kinescope performed well (but with only 80 lines definition), and the transmitter was still of a mechanical type. A "breakthrough" would come when the Zworykin team decided to develop a new type of cathode ray transmitter, one described in the French and British patents of 1928 priority by the Hungarian inventor Kalman Tihanyi whom the company had approached in July 1930, after the publication of his patents in England and France. This was a curious design, one where the scanning electron beam would strike the photoelectric cell from the same side where the optical image was cast. Even more importantly, it was a system characterized by an operation based on an entirely new principle, the principle of the accumulation and storage of charges during the entire time between two scansions by the cathode-ray beam.

According to Albert Abramson, Zworykin’s experiments started in April 1931, and after the achievement of the first promising experimental transmitters, on October 23, 1931, it was decided that the new camera tube would be named Iconoscope. The system was ready to be launched at the end of 1934, a contract had of course been signed with the Hungarian inventor for the purchase of his patents. In early 1935, the new tube was introduced in Germany. It was soon developed there, with some improvements, and was successfully used at the 1936 Berlin Olympic Games as one of several cameras, including Philo Farnsworth’s Image Dissector, for film transmission only, broadcasting the games to some two-hundred public theaters. Although the tube went through a number of adjustments and improvements, it continued to be called by the generic name of Iconoscope.

The developments in England, by the British firm Marconi/EMI, followed the original charge storage design under a patent exchange. This electronic system was officially adopted by the BBC whose experimental public broadcasts began in England in November 1936 and initially included the Baird-system. The British electronic system featured 405 scanning lines, while German television adopted 441 line scanning and so did RCA following the initial (1934) 375 line definition.

Legacy

He was inducted into the New Jersey Inventor’s Hall of Fame; and the National Inventors Hall of Fame Additionally, Tektronix in Beaverton, Oregon has named a street on their campus after Zworykin. Albert Abramson wrote the definitive biography on Zworykin in 1995.

Second marriage and calling

Vladimir Zworykin married for a second time in 1951. His wife was Katherine Polevitzky, a Russian-born professor of bacteriology at the University of Pennsylvania. It was the second marriage for both. The ceremony was in Burlington, New Jersey. He retired in 1954.

But new frontiers in medical engineering and biological engineering appealed to him, and he became a founder and first President of the International Federation for Medical and Biological Engineering. The Federation continues to honor outstanding research engineering with a Zworykin Award, the prize being travelling funds to the Award’s presentation at a World Congress.

Honors

Throughout his steady rise in rank, he remained involved in the many important developments of the company and received several outstanding honours, including, in 1934, the Morris Liebmann Memorial Prize from the Institute of Radio Engineers.

He was awarded the Howard N. Potts Medal from The Franklin Institute in 1947.

He received the first Eduard Rhein Ring of Honor from the German Eduard Rhein Foundation in 1980.

From 1952 to 1986 the IEEE made awards to worthy engineers in the name of Vladimir K. Zworykin. More recently the Zworykin Award has been bestowed by the International Federation for Medical and Biological Engineering.